Impact of donepezil use in routine clinical practice on health care costs in patients with Alzheimer's disease and related dementias enrolled in a large medicare managed care plan: a case-control study.

BACKGROUND: Clinical studies have shown efficacy of cholinesterase inhibitors (eg, donepezil) in mild to moderate Alzheimer's disease (AD). However, there are limited studies examining the impact on health care costs of cholinesterase inhibitors prescribed in routine clinical practice.
OBJECTIVE: The purpose of this study was to estimate the impact of donepezil use on health care costs and utilization in patients with mild to moderate AD and related dementias.
METHODS: This case-control study was conducted using data from the Health Insurance Plan of Greater New York (New York, New York). Data from patients with predominantly mild to moderate AD and related dementias who were enrolled in this Medicare managed care plan from January 1, 1999, to December 31, 2002, were included. The health care costs and utilization of patients who had received donepezil prescribed in routine clinical practice were compared with those of patients who had never received donepezil or other cholinesterase inhibitors (control group). The 2 study groups were matched for age, sex, number of comorbid conditions, and presence of complications of late-stage dementia. Regression analysis was used to estimate the impact of donepezil use on health care costs and utilization during a 12-month follow-up period, controlling for characteristics associated with the outcomes. The analyses did not use a direct measure of disease severity but instead used proxy measures of severity based on medical conditions associated with late-stage dementia.
RESULTS: Data from 687 patients were included in the study. The donepezil group comprised 229 patients (140 women, 89 men; mean age, 79.6 years); the control group, 458 patients (280 women, 178 men; mean age, 80.0 years). The mean costs of medical services per year in the donepezil group were US $2500 (95% CI, $300-$4671) less than those in the control group (P = 0.024). Lower medical costs in the donepezil group ($3325; 95% CI, $1163-$5486; P < 0.003 vs controls) were largely attributable to the lower costs of services performed in the hospital ($2594; 95% CI, $846-$4341; P < 0.004 vs controls) and postacute skilled nursing facility (SNF) ($1012; 95% CI, $444-$1579; P < 0.001 vs controls), which were partially offset by $1241 in higher prescription, physician's office, and outpatient hospital costs. Patients receiving donepezil had shorter mean lengths of stay in the hospital (3.00 vs 5.43 days; 95% CI, 0.66-4.19; P < 0.008) and postacute SNF (0.42 vs 3.40 days; 95% CI, 1.28-4.69; P < 0.001) but a higher mean number of physician's office visits (10.91 vs 7.91 visits; 95% CI, 1.63-4.36; P < 0.001) compared with controls.
CONCLUSIONS: In this case-control study in patients with predominantly mild to moderate AD and related dementias, donepezil therapy prescribed in routine clinical practice was associated with reduced health care costs to the Medicare managed care plan studied. The findings support previous pharmacoeconomic studies with larger sample sizes obtained over a longer period of time, and with improved case-matching criteria.